Contribuição ao conhecimento químico de plantas do Nordeste do Brasil: Cordia piauhiensis Fresen e Triphsia trifolia (Burm. f.) P. Wils

Abstract

The chemical composition of the essential oils from leaves and fruits of Triphasia trifolia were analyzed by GC-FID and GC-MS. The major constituents identified for oils obtained from leaves were sabinene (39.2 and 33.8%) and myrcene (21.9 and 33.6%), while the prevalent compounds detected in fruit oils were sabinene (35.5 and 22.8%), -pinene (21.2 and 29.9) and -terpinene (18.4 and 12.9%). The leaf oils showed moderate antimicrobial activity. The fruit decoction was also investigated leading to the isolation of the coumarins isopimpinelin, (R)-byakangelicin and (S)-mexoticin. From the leaves the coumarins (R)-byakangelicin, aurapten, (S)-mexoticin, isosibiricin, isomerazin and coumurrayin and, the flavonoid vitexina were isolated. All coumarins showed cholinesterase inhibition on TLC test. From Cordia piauhiensis Fresen (Boraginaceae), five triterpenoid saponins were isolated. Their structures were characterized as 3-O--L-rhamnopyranosyl-(1_2)--Dglucopyranosyl pomolic acid, 3-O-[-L-rhamnopyranosyl-(12)--D-glucopyranosyl] pomolic acid 28-O-[-D-glucopyanosyl-(16)--D-glucopyranosyl] ester, 3-O-[-Lrhamnopyranosyl-( 12)--D-glucopyranosyl] ursolic acid 28-O-[-D-xilopyranosyl- (1_2)--D-glucopyanosyl-(16)--D-glucopyranosyl] ester, 3-O--L-rhamnopyranosyl- (12)--D-glucopyranosyl pomolic acid 28-O--D-glucopyranosyl ester and 3-O--Lrhamnopyranosyl-( 12)--D-glucopyranosyl oleanolic acid 28-O--D-glucopyranosyl- (16)--D-glucopyranosyl ester. The structures were established using a combination of 1D and 2D (1H-1H-COSY, HMQC, HMBC, TOCSY and NOESY) NMR techniques, ESIMS and chemical evidences.